52 research outputs found

    From green remediation to polymer hybrid fabrication with improved optical band gaps

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    The present work proposed a novel approach for transferring high-risk heavy metals tometal complexes via green chemistry remediation. The method of remediation of heavy metals developed in the present work is a great challenge for global environmental sciences and engineering because it is a totally environmentally friendly procedure in which black tea extract solution is used. The FTIR study indicates that black tea contains enough functional groups (OH and NH), polyphenols and conjugated double bonds. The synthesis of copper complex was confirmed by the UV-vis, XRD and FTIR spectroscopic studies. The XRD and FTIR analysis reveals the formation of complexation between Cu metal complexes and Poly (Vinyl Alcohol) (PVA) host matrix. The study of optical parameters indicates that PVA-based hybrids exhibit a small optical band gap, which is close to inorganic-based materials. It was noted that the absorption edge shifted to lower photon energy. When Cu metal complexes were added to PVA polymer, the refractive index was significantly tuned. The band gap shifts from 6.2 eV to 1.4 eV for PVA incorporated with 45 mL of Cu metal complexes. The nature of the electronic transition in hybrid materials was examined based on the Taucs model, while a close inspection of the optical dielectric loss was also performed in order to estimate the optical band gap. The obtained band gaps of the present work reveal that polymer hybrids with sufficient film-forming capability could be useful to overcome the drawbacks associated with conjugated polymers. Based on the XRD results and band gap values, the structure-property relationships were discussed in detail. © 2019 by the authors. Licensee MDPI, Basel, Switzerland

    A study of tensile test on open-cell aluminum foam sandwich

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    Aluminum foam sandwich (AFS) panels are one of the growing materials in the various industries because of its lightweight behavior. AFS also known for having excellent stiffness to weight ratio and high-energy absorption. Due to their advantages, many researchers’ shows an interest in aluminum foam material for expanding the use of foam structure. However, there is still a gap need to be fill in order to develop reliable data on mechanical behavior of AFS with different parameters and analysis method approach. Least of researcher focusing on open-cell aluminum foam and statistical analysis. Thus, this research conducted by using open-cell aluminum foam core grade 6101 with aluminum sheets skin tested under tension. The data is analyzed using full factorial in JMP statistical analysis software (version 11). ANOVA result show a significant value of the model which less than 0.500. While scatter diagram and 3D plot surface profiler found that skins thickness gives a significant impact to stress/strain value compared to core thickness

    Factors Associated with High Prevalence of Intestinal Protozoan Infections among Patients in Sana'a City, Yemen

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    Intestinal protozoan diseases in Yemen are a significant health problem with prevalence ranging from 18% to 27%. The present study is a cross-sectional study aimed at determining the factors associated with the high prevalence of intestinal protozoan infections among patients seeking health care in Sana'a City, the capital of Yemen. (0.4%). Multivariate analysis using forward stepwise logistic regression based on intestinal protozoan infections showed that contact with animals (OR = 1.748, 95% CI = 1.168–2.617) and taking bath less than twice a week (OR = 1.820, 95% CI = 1.192–2.779) were significant risk factors of protozoan infections. infections being most common. Statistical analysis indicated that low personal hygiene and contact with animals were important predictors for intestinal protozoan infections. As highlighted in this study, in order to effectively reduce these infections, a multi-sectoral effort is needed. Preventive measures should include good hygienic practices, good animal husbandry practices, heightened provision of educational health programs, health services in all governorates including rural areas. Furthermore, it is also essential to find radical solutions to the recent water crises in Yemen

    Anterograde trafficking of KCa3.1 in polarized epithelia is Rab1- And Rab8-Dependent and recycling endosome-independent

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    The intermediate conductance, Ca2+-activated K+ channel (KCa3.1) targets to the basolateral (BL) membrane in polarized epithelia where it plays a key role in transepithelial ion transport. However, there are no studies defining the anterograde and retrograde trafficking of KCa3.1 in polarized epithelia. Herein, we utilize Biotin Ligase Acceptor Peptide (BLAP)-tagged KCa3.1 to address these trafficking steps in polarized epithelia, using MDCK, Caco-2 and FRT cells. We demonstrate that KCa3.1 is exclusively targeted to the BL membrane in these cells when grown on filter supports. Following endocytosis, KCa3.1 degradation is prevented by inhibition of lysosomal/proteosomal pathways. Further, the ubiquitylation of KCa3.1 is increased following endocytosis from the BL membrane and PR-619, a deubiquitylase inhibitor, prevents degradation, indicating KCa3.1 is targeted for degradation by ubiquitylation. We demonstrate that KCa3.1 is targeted to the BL membrane in polarized LLC-PK1 cells which lack the m1B subunit of the AP-1 complex, indicating BL targeting of KCa3.1 is independent of μ1B. As Rabs 1, 2, 6 and 8 play roles in ER/Golgi exit and trafficking of proteins to the BL membrane, we evaluated the role of these Rabs in the trafficking of KCa3.1. In the presence of dominant negative Rab1 or Rab8, KCa3.1 cell surface expression was significantly reduced, whereas Rabs 2 and 6 had no effect. We also co-immunoprecipitated KCa3.1 with both Rab1 and Rab8. These results suggest these Rabs are necessary for the anterograde trafficking of KCa3.1. Finally, we determined whether KCa3.1 traffics directly to the BL membrane or through recycling endosomes in MDCK cells. For these studies, we used either recycling endosome ablation or dominant negative RME-1 constructs and determined that KCa3.1 is trafficked directly to the BL membrane rather than via recycling endosomes. These results are the first to describe the anterograde and retrograde trafficking of KCa3.1 in polarized epithelia cells. © 2014 Bertuccio et al

    Determining system boundaries on commercial broiler chicken production system using ISO 14040/14044 guideline: a case study

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    The demand of poultry product in Malaysia market shows an escalation throughout the year and expected to increase in the future. The expansion of poultry production has led to environmental concern in relation to their operational impact to environmentAt present, assessment of waste management of poultry production in Malaysia is lacking. A case study research was conducted in a commercial broiler farm to identify and assess the system boundaries in the lifecycle supply chain of broiler chicken production using ISO 14040/44 guidelines. ISO 14040/44 standard includes Life Cycle Assessment (LCA) framework guidelines to evaluate environmental influence associated with a product/process throughout its life span. All attributes associated with broiler operation is defined and the system boundaries is determined to identify possible inputs and outputs in the case study. This paper discuss the initial stage in the LCA process, which set the context of the research and prepare for the stage of Life Cycle Inventory

    Inventory data on commercial broiler chicken production system using life cycle assessment approach: A case study

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    An inventory analysis of the life cycle of broiler chicken production from cradle-to-gate perspective was carried out with the aim to identify possible input and output parameters involved in the system. To do so, broiler chicken production in Myra Chicken Farm and Services was investigated in detail. Result shows the inventory data on feed consumption, transportation, physical performance parameter and other utilities that affect the product which is broilers. Broilers production in fact shows escalation year by year because of high demand from consumer. A cradle-to-gate assessment was conducted based on ISO 14040/14044 guidelines. Inventory data was gathered from farmers and available literature. Improving all the input and output system will increase the level of productivity and the cost of the production. Thus, at the end of the research, it will able to make industry player to understand and take into consideration the solutions in order to promote a green broiler chicken productio

    Assessment of flank wear and tool life in high speed face milling under dry and near dry machining

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    One of the leading environmental pollution sources related to machining industry is the massive amount of cutting fluids used. However, coolant performs many advantages, such as chip removal and reducing the cutting zone temperature. This research aims to analyze the effect of dry machining and near dry machining on flank wear progress in high-speed face milling. Two sets of experiments using Box Behnken Design (BBD) as a part of Response surface methodology (RSM) have been conducted for both dry machining and near dry machining on milling AISI 1050 using five coated carbide inserts (TNGA 160408) for each treatment. The flank wear in both dry and near dry machining was measured using Hisomet II Tool Maker Microscope. The boundaries of the variables in this research are 613-817 (m/min) cutting speed, 100-200 (mm/min) feed rate, and 0.1-0.2 (mm) depth of cut. The results show that at high speed near dry milling, the flank wear and the tool life was better as compared with the dry machining. A new mathematical model for flank wear and tool life has been developed. In conclusion, near dry machining proved to be a better option at high speed

    Influence of the angle of cut of workpiece on taper and corner roundness during Wire Electrical Discharge Machining (WEDM)

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    Wire electrical discharge machining (WEDM) is a unique machining technique which is capable of machining parts with high degree of complexity regardless of their hardness. However, when high precision and accuracy are needed, the taper and corner roundness on the workpiece machined need to be controlled to ensure that the parts can perform their intended function. Parameters such as angle of the profile cut; peak current (IP) and wire speed (WS) might affect the taper and the corner roundness of the machined workpiece. To know the sharpness of the profile, the corner roundness and taper of the kerf should be assessed. Hence, to assess the influence of IP and WS on angle of the profile cut, the design of experiment (DOE) was used for this investigation. By employing full factorial design of DOE, eight runs were conducted for each of the responses which are corner radius and taper angle. The experiments were performed by using brass as the wire electrode and stainless steel 304 (SS 304) as the workpiece. The taper (in terms of angle) is calculated by using the value of kerf width at the top and bottom of the cut. The corner roundness was also measured using a measuring microscope. It was found that the degree of angle of cut and IP have a significant effect on taper angle and corner roundness while the significance of WS is low. From the analysis, it is found that the optimum value of the angle of the cut, IP and WS are 117.47°, 5.00A and 10.00 mm/s respectively. By knowing the significance of the angle of the profile cut, IP, and WS and the optimum values, the profile with low taper and sharp corner can be achieved
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